Proxy Server Deployment

You can stick proxies at the exit points
of local networks to control the traffic flow between the local
network and the greater Internet. You might use egress proxies in a
corporation to offer firewall protection against malicious hackers
outside the enterprise or to reduce bandwidth charges and improve
performance of Internet traffic. An elementary school might use a
filtering egress proxy to prevent precocious students from browsing
inappropriate content.

Proxies are often placed at ISP access
points, processing the aggregate requests from the customers. ISPs
use caching proxies to store copies of popular documents, to improve
the download speed for their users (especially those with high-speed
connections) and reduce Internet bandwidth costs.